algebra 1
posted by Anonymous .
The rocket coaster has 15 cars, some that hold 4 people and some that hold 6 people. There is a room for 72 people altogether. How many 4 passenger cars are there? How many 6 passenger cars are there?

let the number of 4people cars be x
then the number of 6person cars is 15x
4x + 6(15x) = 72
4x + 90  6x = 72
2x = 18
x = 9
9 of the 4person cars and 6 of the 6person cars